If you were too chicken (*buckawwww*) to try out the Skyrim 1.6 beta patch that went up on Steam a few weeks ago, there's a wee surprise waiting for you on: the real, full, actual 1.6 patch for Bethesda's RPG is now up there. It has fixes, optimisations, and the addition of Horseback Combat that Bethesda added for the hell of it.
So it's a bit game-changing: you can chop one-handed swords and fire bows from the equine conveyances, although magic is oddly absent. It gives your character a better chance to swoop around potential enemies, hitting and running and, if you're anything like me, shouting "I'm on a horse trololololol" at the confused AI. But I did find it a bit clunky compared to ground-based combat: it really feels like an addition than something the game was built around, but I'm also very bad at it.
Alongside the new fighting dynamic, there are some tightening of bolts, mostly aimed at stopping the game from crashing like a dead dragon, but really all you should care about is hitting things from the top of a horse.